KDog said..
I weigh a little bit more than you 82 kg own the 8-10 where I live the water is always moving around as you say wish I had gone with the 8-8 at 124 lit it would have been just a bit better than the 8-10. You want these boards to sit low in the water it just kinda ads to the stability don't worry so much about the width you'll get used to it.
I am the same weight and age and Kdogs comments apply to me swell